Xu Hanli, Wang Cunbao, Liang Zhiwei, He Liyi, Wu Weixiang
Department of Environmental Engineering, Institute of Environmental Science and Technology, Academy of Water Science and Environmental Engineering, Zhejiang University, Zijingang Campus, 866# Yuhangtang Road, Hangzhou, Zhejiang, 310058, People's Republic of China.
Appl Microbiol Biotechnol. 2015 Apr;99(8):3673-83. doi: 10.1007/s00253-014-6300-8. Epub 2014 Dec 23.
The differences in the structure and component characteristics of partial nitrification biofilms between autotrophic and heterotrophic conditions were investigated in this work. Three-dimensional excitation-emission matrix fluorescence spectroscopy (EEM), fluorescence staining, and confocal laser scanning microscopy (CLSM) were used to determine differences in the architecture and extracellular polymeric substance (EPS) distribution of the autotrophic and heterotrophic biofilms. Partial nitrification was successfully achieved, and the results demonstrated that an appropriate amount of organic carbon (chemical oxygen demand (COD)/N = 2.6) is advantageous for obtaining better partial nitrification. The final ammoniation and nitrosation rates achieved were 97 and 99 %, respectively. Proteins (PN) and polysaccharides (PS) were dominant in the tightly bound EPS (TB-EPS) of autotrophic and heterotrophic biofilms, with PN/PS ratios of 0.96 and 0.69, respectively. Proteins, lipids, α-D-glucopyranose polysaccharides, and nucleic acids were mostly present within the layers of biofilms, but they were distributed in the upper-middle portion of the autotrophic biofilm and increased with depth from the upper layer in the heterotrophic biofilms.
本研究考察了自养和异养条件下部分硝化生物膜的结构和组分特征差异。采用三维激发-发射矩阵荧光光谱（EEM）、荧光染色和共聚焦激光扫描显微镜（CLSM）来确定自养和异养生物膜在结构和胞外聚合物（EPS）分布上的差异。成功实现了部分硝化，结果表明适量的有机碳（化学需氧量（COD）/N = 2.6）有利于获得更好的部分硝化效果。最终的氨化率和亚硝化率分别达到97%和99%。蛋白质（PN）和多糖（PS）在自养和异养生物膜的紧密结合EPS（TB-EPS）中占主导地位，PN/PS比值分别为0.96和0.69。蛋白质、脂质、α-D-吡喃葡萄糖多糖和核酸大多存在于生物膜层内，但它们分布在自养生物膜的中上部，而异养生物膜中则从上层到深层含量增加。
